Alopecia areata is a common presentation of Saudi patients seen at dermatology clinics. Although autoimmune factors have been suggested as pathogenic factors, alopecia areata remains a disease of unknown etiology. We investigated 92 patients with alopecia areata as compared to 88 sex- and age-matched healthy control subjects for the prevalence of associated diseases as well as abnormalities of thyroid function, and for the frequency of anti-thyroid antibodies. We found that atopy and pscychological stress constitute the most commonly associated disorders in our series. Except for two female patients with diabetes mellitus, none of the remaining patients displayed clinical evidence of endocrine or autoimmune disease. Only one patient had high T(3) and T(4) values and five (5.4%) had low titers of anti-thyroid antibodies, an acceptable finding for the normal population.